Ziproxy vs Janus vs PageSpeed Module - comparison of compression proxies

Only 27% of the global population has access to a fast internet (over 10 Mbps) and hundreds of millions of people around the world have a limited Internet connection. This is where a data compression proxy (a.k.a. web accelerator) comes to the rescue. It optimizes loading of web pages by minimizing HTML/CSS/JS, enabling gzip compression, re-encoding images, etc.

Some time ago I was comparing proxies in the cloud: Mozilla Janus, Opera Turbo and Google Compression Proxy. Now I am testing open source HTTP forwarding proxies: Ziproxy, Mozilla Janus and Google PageSpeed Module (mod_pagespeed) for Apache with mod_proxy, all installed on my premise. This time the primary factor is not loading time, but total size of various web pages.

	Ziproxy	Janus	PageSpeed	Direct
ZDNet	1026 KB	1117 KB	802 KB	1225 KB
TheNextWeb	3768 KB	3638 KB	3672 KB	4156 KB
New Yorker	4528 KB	4872 KB	4782 KB	5357 KB
AntyWeb	1258 KB	2750 KB	1928 KB	3493 KB
iStockPhoto	2905 KB	3699 KB	3444 KB	3756 KB
Total	13485 KB (25% saved)	16076 KB (11% saved)	14628 KB (19% saved)	17987 KB

The best compressing HTTP proxy is Ziproxy with 25% of data savings. The second place goes to Google PageSpeed with 19%. Mozilla Janus was the worst with only 11% saved.

All the proxies were tested with equal image quality settings (60%).